Bus Width - NEC V850E/MS1 UPD703100 User Manual

4.5.3 Bus width

V850E/MS1 carries out peripheral I/O access and external memory access in 8, 16, or 32 bits. The following
shows the operation for each access. All data is accessed in order from the lower side.
(1) Byte access (8 bits)
(a) When the data bus width is 16 bits
<1> Access to address 2n (even address)
7
0
Byte
data
Remark n = 0, 1, 2, 3, ···
(b) When the data bus width is 8 bits
<1> Access to address 2n (even address)
7
0
Byte
data
Remark n = 0, 1, 2, 3, ···
CHAPTER 4 BUS CONTROL FUNCTION
Address
15
8
7
2n
0
External
data bus
Address
7
2n
0
External
data bus
User's Manual U12688EJ4V0UM00
<2> Access to address 2n + 1 (odd address)
15
8
7 7
0 0
Byte External
data data bus
<2> Access to address 2n + 1 (odd address)
7 7
0 0
Byte External
data data bus
Address
2n + 1
Address
2n + 1
109